The Running Girl
by HelaofHelheim
Summary: Someone new turns up on Baker Street. Someone who may understand Sherlock more than anyone. Who is she? Can she be trusted? I own nothing. Set after Season 3 Finale & Abominable Bride.
1. Chapter 1

The Running Girl

Every day right at 3 in the afternoon John had noticed something new happening on Baker Street. A young woman running down the street right past 221B. She sported purple jogging capri's, a green shirt, and blue and purple running shoes. She always seemed to glance up at the door of the flat but John thought nothing of it.

One day when John was particularly bored and waiting for Sherlock, he stared out the window. He felt that something was off, glanced at his watch, and then back out to the street. It was 3 o clock. The girl wasn't anywhere in sight. Twenty more minutes passed. Sherlock always took forever to get ready for a dinner out. _Where is she?_

"Strange.." he mumbled to himself.

"What is?" Sherlock asked turning the collar of his shirt down and fixing his cuffs as he walked in the room.

"Hm? Oh just something I noticed. There's a woman runs down the street every day. Has for the last month. But today," he looked at his watch again, 3:30. "She hasn't shown."

"She could be ill? Injured? Murdered?" Sherlock almost sounded happy with the last option. That's what he needed was a good murder. Ever since Moriarty's face showed up on every screen in England, it had been quiet. Not one interesting murder. John figured Sherlock was right as he almost always is and they grabbed their coats and walked downstairs to the door. Sherlock stepped out into the crisp winter air as John said goodbye to Mrs. Hudson. Just then the running girl came into view. Sherlock noticed out of the corner of his eye and turned in her direction. He acted as if he was watching for a cab but kept his eye on her as well. She kept her gaze down and slowed to a walk as she approached them. John closed the door behind him and stood on the steps watching her. She glanced up and locked eyes with Sherlock just for a moment. She passed between them looking back down. When she was well past them she sped up to a run again and turned the corner disappearing out of site. Sherlock watched after her, obviously put off by their exchange.

"You alright?" John asked.

"Fine." Sherlock watched a little longer seemingly lost in his thoughts but then pulled back to reality. He waved a cab down and they got in.

"You're sure you're alright?" John said skeptically.

"Yes I'm fine." Sherlock snapped irritably, looking out the window of the cab. John didn't believe him but decided not to push any further for now. They still had to go by his and Mary's flat to pick up the mother-to-be and get to the restaurant. Mary was so close to having the baby, John almost hated going out. What if she went into labor in the middle of the restaurant? _I'm a doctor I shouldn't be worried. I know how to handle these things."_ He thought. He still couldn't shake his anxiety, though.

His worst fears were realized. Right after they ordered, Mary's water broke. They rushed to the hospital and quickly made it to a room and got Mary comfortable. Sherlock, not wanting to be in a hospital ward full of screaming women and crying newborns, took his leave. He arrived home at 221B Baker Street to see someone sitting on his doorstep.

Sherlock smirked. "I figured I'd see you tonight."


	2. Chapter 2

**ONE WEEK LATER**

"I wonder how Sherlock's doing? Haven't heard from him all week." John said playing with his newborn baby girl in the back seat of the car. Mary got in on the other side.

"I'm sure he's fine, darling, we're going by there on the way home." She buckled her seat belt and looked up at John. "You're driving."

"Right." John quickly got up and closed the back door and got in up front.

They pulled up in front of 221B Baker Street and parked. John quickly got out to help Mary and grab the baby carrier. They walked in and saw Mrs. Hudson, showing her the new little Watson. John heard laughter upstairs. Not Sherlock's. A woman's? He and Mary walked up the stairs to the flat.

"Sherlock? We have someone we want you to meet." He said pushing the already cracked door open. There was Sherlock, sitting in his chair as always, but sitting on the arm of the chair was someone that left John at a loss for words. _The Running Girl_. They were watching some crap telly show.

"Look at the color of his hair! He's obviously not cheating on her." Early 20's John thought.

"No, no. But she _is_ cheating on him. Guilt that's what that is." Sherlock scoffed. He noticed John and Mary and got up to greet them.

"Ah! John, Mary," He grinned at them, then looked down at the baby carrier and at the beautiful little baby inside. "And child." His smile dropped a little. He didn't know how to feel about the little creature.

The girl stood up as well. She was short. Red hair, dark eyes. She turned with a smile to meet the Watsons but as her eyes fell on Mary, a look of shock crossed her face for just a second but she hid it well. She dropped her eyes. "Hello there." She said with an almost pained smile.

"Oh yes. John, Mary. This is Ellie." To be fair John and Mary were just as shocked to see Sherlock actually enjoying himself with another human being. Ellie glanced up at Sherlock.

"I'm going to run to the store. I'll be back." She grabbed her coat and walked toward the door passing John and Mary. "Lovely to meet you." She still couldn't look at them. She disappeared down the stairs.

John was so confused. "What…who?"

Sherlock furrowed his brow. "John, are you having a stroke?" John snapped out of his stuttering state, shooting Sherlock a look for the insult.

"No, I'm just… who was that again?"

"Ellie. Did you not hear me when I introduced you? That's quite rude, John. Really not like you." Sherlock moved back to his chair and turned the tv off. Mary sat down at the desk with the baby carrier in front of her. She picked the baby up and smiled at Sherlock, almost devilishly. "You wanna hold her?" Sherlock went pale.

 _No, no, no, no_. Ellie thought. _How can this be?!_

She typed in a number on her phone and hit the call button, turning the corner from Baker Street. _That woman. The woman that John Watson just strolled in with_. Ellie felt every muscle in her body tense up at the very thought of her. She hadn't seen her in years. The ringing stopped and a familiar voice picked up the other end.

"What?" The voice said.

"Why didn't you tell me?" Ellie tried not to yell and attract attention.

"Because you would've reacted, like you're reacting now. I hired you to do this job, now do it. No questions. No problems. Keep your cover with Sherlock. Don't touch Mary." The phone went dead.

"A week ago you hadn't had any interaction with her except for that moment on the street. And now you're watching TV making deductions with her like old friends?" John couldn't get past this. He lowered his voice. "Is this another Janine scheme?" Sherlock gave him an irritated look. "Of course not."

Mary walked over to Sherlock with the baby girl. She bent down to hand her to Sherlock. "Mary I really don't think- Please don't-" but by the time he got his objections out, he was awkwardly holding the child. He stared down at her with an almost scared look. John held in a chuckle at the site of Sherlock holding a baby. It was unnatural. Putting an end to Sherlock's unease, John took his infant from him and put her back in her carrier. He still couldn't shake this weird concern for Sherlock's new friend.

"So she's clever, then, like you?" John asked.

"Yes." Sherlock looked away and lowered his voice. "Her IQ is just higher than mine."

Mary giggled at Sherlock's embarrassment.

"Only by 2!" He snapped.

"Oh don't worry Sherlock you're still our favorite sociopath." Mary laughed. "I'm going to put the baby in the car, John." She kissed John's cheek and went down the stairs.

John looked at Sherlock who was staring out the window. "Do you know how incredibly invigorating it is to have a conversation with someone who can follow your train of thought?" John should've felt insulted but he understood. Sherlock's mind was wild and for him to have someone other than Mycroft who can understand it was good.

"Have you been keeping clean?" John asked changing the subject.

"Yes." Sherlock huffed at window, turned around and picked up his violin. He began to play the song he had when dealing with the scandal in the royal family and 'The Woman.' John new this meant he wasn't going to talk anymore and went to leave. Sherlock stopped playing.

"When I came home from the hospital that night, she was sitting on the steps…


	3. Chapter 3

**AN: Hey guys so I'm sorry its taken me so long. This story has been coming along in the most random order, so please bare with me. It is a work in progress and it could change at any time. I am working on more and will try to get it up soon. Until then here is a little bit to tide you over. Please Please feel free to review and give your opinion. Thanks!** **~H**

 _1 Week Prior_

"I figured I'd see you tonight." Sherlock approached his doorstep.

"Did you?" The girl looked up to meet his gaze. Sherlock looked up and marched up the stairs past her. "Tea?" He sighed, opening the door. She remained silent and got up, following him in and closing the door behind them.

The two sat in silence for a long while, she in John's chair and Sherlock in his. They stared at each other. Sherlock observed that she had not changed out of her running clothes from this morning and looked positively pitiful. She had sat in the rain waiting for him.

"You haven't touched your tea." Sherlock said, eyes still locked on hers, hands steepled at his chin.

"And you haven't touched yours."She raised her eyebrows, glancing down at his cup then back up to him. Sherlock sighed impatiently dropping his hands to the arm rests of the chair.

"Why are you here?"

"Oh, you haven't _deduced_ it yet?" She held in a smile. "You invited me."

"I invited you in because you looked _not_ boring which would be a change from recent cases but apparently I misjudged which does not happen often I assure you. So," He paused. The girl took this as her chance to speak up, swallowing her sip of tea. "I'm a client." She set her cup down. "Hell, I'm almost family." Sherlock gave her a confused look. She held her hand out to shake his. "Ellie, your future sister-in-law."

Sherlock didn't move, confusion still evident in his expression. Ellie raised an eyebrow then finally pulled her arm back, cocking her head to one side. She could see a million questions buzzing around in his head, so she decided to try and answer a few. "I am engaged to Sherrinford Holmes. I have been for 6 months." Confusion was then replaced with shock. "But he's been missing for a month and a half now..." She dropped her gaze. Sherlock stood and walked to the window.

"Sherrinfords…alive?" His voice was barely a whisper. Ellie looked back up at the detective, brow furrowed. "When he said he had lost contact with his brothers, I didn't think it was this bad."She quietly got up and went over to him, putting a hand on his arm. "Are you alright?"

He cleared his throat. "Of course I am. Why wouldn't I be?" He turned and walked to the door to the stairs. Sherlock picked up the Belstaff off the arm of the sofa where he had dropped it and threw it on. Ellie watched him, slightly baffled. "Where are you going?" "To see my brother." He said turning to leave. She followed him out into the stairwell. "But he's missing." "Not that brother." He was already down the steps and out the door before she could say anything else.


End file.
